Purpose <p>Despite the increasing understanding of femoroacetabular impingement (FAI), the impact of specific patient characteristics, including inflammatory pathologies like axial spondyloarthritis (axSpA), on its pathophysiology and clinical outcomes following treatment remains inadequately defined. Therefore, the purpose of this scoping review was to evaluate the relationship between FAI and sacroiliac (SI) joint abnormalities and FAI and axSpA.</p> Methods <p>The study was conducted following the framework established by Arksey and O’Malley and Levac et al., adhering to the PRISMA scoping review extension checklist. A systematic search was performed across MEDLINE, EMBASE, and Cochrane Library databases for articles published until August 2024. A total of 120 articles were screened and eight finally met the inclusion criteria.</p> Results <p>The review analysed data from the eight retrospective studies with a total of 1,723 patients. We found that the prevalence of SI joint abnormalities in patients with FAI can be as high as 25–28%. Furthermore, the prevalence of FAI morphology in patients with axial spondyloarthritis can be as high as 20–37%. Finally, patients undergoing hip arthroscopy for FAI with axSpA and/or SI joint abnormalities have lower postoperative outcome scores reported in comparison with those patients who do not have these comorbidities.</p> Conclusion <p>Over a quarter of patients with FAI can have concomitant radiographic SI joint abnormalities. We cannot overemphasise the importance of assessing the spine, specifically the SI joint, and ruling out symptoms emanating from the SI joint in all patients with FAI. There is clearly a knowledge gap in understanding the underlying pathophysiology linking FAI and axSpA. We require further research to elucidate the underlying mechanisms of this relationship, standardise evaluation methods, and explore long-term outcomes in this cohort of patients.</p>